Roof Fan Tray 120V - Black
By APC

For increased ventilation, roof mounted Fan Tray Kits are available for both the 42U and 22U model enclosures. Zero U space is required as the fan trays mount quickly and easily into the roof of the enclosures. Both fan tray kits feature two 4" cable access holes (with removeable caps) which align with the access holes in the 42U roof. ... 

SmartRack Roof Mount Fan Panel - 230V
By Tripp Lite

A complete line of SmartRack accessories are available to customize your SmartRack to your application. Designed for easy installation and years of reliable service, SmartRack accessories from Tripp Lite are ideal compliments to your SmartRack enclosure or open frame rack system. ...